EP0682999A2 - Article molded from metal powder and process and apparatus for preparing the same - Google Patents

Article molded from metal powder and process and apparatus for preparing the same Download PDF

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Publication number
EP0682999A2
EP0682999A2 EP95105492A EP95105492A EP0682999A2 EP 0682999 A2 EP0682999 A2 EP 0682999A2 EP 95105492 A EP95105492 A EP 95105492A EP 95105492 A EP95105492 A EP 95105492A EP 0682999 A2 EP0682999 A2 EP 0682999A2
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EP
European Patent Office
Prior art keywords
blank
die
undercut
pressed
pressing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP95105492A
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German (de)
French (fr)
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EP0682999A3 (en
EP0682999B1 (en
Inventor
Rainer Dipl.-Ing. Schmitt
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GKN Sinter Metals GmbH
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Ringsdorff Sinter GmbH
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Publication date
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Publication of EP0682999A3 publication Critical patent/EP0682999A3/en
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/16—Both compacting and sintering in successive or repeated steps
    • B22F3/164—Partial deformation or calibration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/02—Compacting only
    • B22F3/03—Press-moulding apparatus therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F5/10—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of articles with cavities or holes, not otherwise provided for in the preceding subgroups
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/02—Dies; Inserts therefor; Mounting thereof; Moulds
    • B30B15/022—Moulds for compacting material in powder, granular of pasta form

Definitions

  • the invention relates to a pressed part made of metal powder, in particular a sintered part with at least one undercut lying transversely to the pressing direction, together with a method and device for its production with the features in the preamble of the independent claims.
  • a sintered metal body which has undercuts lying transverse to the pressing direction.
  • the sintered metal body is constructed in several parts.
  • the individual shaped parts are put together to form a component and then bonded to one another by applying a magnetite layer to their surfaces. Due to the multi-part nature of the sintered metal body, this procedure requires a certain amount of construction and process effort.
  • the undercuts can also be subsequently machined into the sintered metal body.
  • the possibility of combining the individual parts of a multi-part sintered metal body by welding or soldering is also addressed. These techniques also mean an increased construction and process effort, which is reflected in the cost and in the economy of the pressed part to be produced.
  • the pressed or sintered part according to the invention which is produced by powder metallurgy, is characterized by undercuts formed in one piece, i.e. the undercuts are formed on a pre-pressed one-piece blank during a pressing process, preferably during calibration.
  • the blank is already in the sintered state.
  • the aforementioned procedure eliminates the need to assemble previously separately pressed individual parts and / or costly post-processing.
  • the one-piece design of the blank eliminates tolerance problems, e.g. caused by adding existing over- or undersizes to parts to be joined.
  • the method according to the invention can be carried out more quickly, simply and cost-effectively.
  • the undercuts are formed on the blank during calibration by material displacement.
  • the blank can be compacted. For example, also press a punch or slide across the blank and press in the undercut.
  • the base of the undercuts is formed by the basic shape of the blank present and, during calibration, only one protruding shoulder is molded on for each undercut. This is preferably done by shifting a material supply in the blank, which forms a protruding shoulder for the differentiation.
  • the material is shifted preferably by means of a movable punch which displaces the material present at a corresponding point in the blank transversely to the pressing direction into a lateral recess located on a die and thereby forms the aforementioned shoulder.
  • the volume of material is at least the same volume as the recess and both, the material supply and the recess are arranged adjacent.
  • the volume of material is preferably somewhat larger in volume than the recess.
  • the material supply is in the form of an elevation on the surface of the blank in the vicinity of the recess in the die which later forms the shoulder.
  • the material supply is in the blank and is pushed into the blank during pressing or calibration by penetration of an attachment located on the press ram.
  • the volume of the attachment is at least as large as that of the recess that later forms the shoulder.
  • the method according to the invention can be carried out in a conventional pressing device.
  • a die adapted to the molding task must be used. This has two or more movable jaws or segments, of which at least one / one has a recess on the pressing surface which corresponds in shape and volume to the shoulder which later projects beyond the undercut.
  • the mold can be opened to remove the finished and calibrated pressed part, which also releases the undercut.
  • a pre-product body is produced by powder metallurgy, in which there is a material reservoir on a surface that is adjacent to the later undercut and that is transverse to the pressing direction during calibration, the volume of which corresponds at least to the volume that in the finished sintered body exceeds the undercut and occupies a limiting shoulder.
  • the pre-product body is then inserted into a die which consists of at least two movable segments and which is in the open state when the segments are moved apart.
  • This die has at least one recess on its inner wall which is equivalent to the intended shape of the at least one shoulder which projects beyond and delimits the undercut in the finished sintered metal part.
  • the pre-product body is inserted into the die in such a way that its area carrying the material reservoir is located at the point at which the corresponding recess in the inner wall of the die for the formation of the shoulder projecting beyond the undercut.
  • the die is then brought into the pressing position with the pre-product body in a die press having at least one press die, the die is closed to a calibration dimension by pressing the segments together, for example by means of a hydraulically or mechanically acting closing device, and the pre-product body is calibrated with a press die using such a pressure that this on it or in the material reservoir located in it is rearranged by flow processes into the recess located in the die wall, thus creating the bulge which is superior and delimiting the undercut.
  • This pressing process removes the press ram from the die, which relieves or removes the closing device spanning the die segments, the die segments are moved outwards in the open position and the finished press part is removed.
  • the pressed part or the blank can consist of any suitable metal powder. It has proven to be advantageous if the blank material has an elongation at break of more than 2%, preferably more than 10%. Suitable materials are e.g. SINT D35 (phosphorus-containing steels), SINT D40 (stainless steel) etc.
  • Figures 1 and 2 show a finished pressed part 7 made of metal powder, preferably in the form of a sintered part. It is preferably made of an alloy steel, but can also have any other suitable metallic composition.
  • the finished pressed or sintered part consists of a metal which has an elongation at break of more than 2%, preferably more than 10%.
  • Suitable materials are e.g. SINT D35 (phosphorus-containing steels) or SINT D40 (stainless steels).
  • the finished press part 7 has at least one undercut 3 lying transversely to the pressing direction. In the exemplary embodiment shown there are two undercuts 3 lying opposite one another in the form of transverse grooves or troughs.
  • Figure 2 illustrates the training in longitudinal section.
  • the undercut 3 has a base 4 and a projecting shoulder 5.
  • the counter shoulder is formed here by a widened head plate 6.
  • the pressing part 7 can be designed in any other way. There can also be only one undercut 3 or even three or more undercuts 3 or an annular groove have, which can also be distributed as desired on the pressing part 7.
  • the finished part 7 receives the undercuts 3 when calibrating a pre-pressed, in the case of a sintered part a pre-pressed and sintered blank 2 consisting of only one part by molding. As shown in FIGS. 3 to 6, the shoulders 5 are formed by shifting the material. The calibration process takes place in a press device 1, which is described and illustrated in more detail below with reference to FIGS. 7 to 11.
  • the blank 2 has a simple shape which can be easily produced by pressing powders optionally provided with a binder and preferably subsequent sintering. In the exemplary embodiment shown, it already has the top plate 6 and a smooth shank or pin 22 which has the approximately barrel-shaped cross section shown in FIG. The blank 2 does not yet have a finished undercut 3 transverse to its pressing direction. The side walls of the shaft or pin 22, however, already form the later bases 4 of the undercuts 3 shown in FIG. 4.
  • the blank 2 has material stocks 8 which are shifted during calibration and which thereby form the new shoulders 5.
  • the material stocks 8 consist of projections 9 protruding in the pressing direction 19.
  • the projections 9 are pressed flat in the pressing device 1 by a punch 12, the material stocks being deflected transversely to the pressing direction 19 and displaced into lateral recesses 16 on a die 14.
  • the shape of the recesses 16 correspond to the shoulders 5 to be formed.
  • the stamp 12 forms the surfaces of the shoulders 5.
  • FIG. 4 shows the shape of the finished pressed part with the undercuts 3 and the molded shoulders 5.
  • the blank 2 has no protrusion 9.
  • the material stocks are integrated into the basic shape of the blank and are therefore not shown separately.
  • the punch 12 has two bump-like profiles 13 on the upper side, which leave a depression 20 in the finished pressed part 7 during calibration. Due to the oblique flanks of the profiles 13, the material of the blank is displaced to the side into the recesses 16 during calibration in the relevant edge regions of the journal. This results in the final shape of the press part 7 shown in FIG. 6 which is enclosed by the press tool.
  • the lower punch 12 can also have a profile protruding in the pressing direction 19. Otherwise, the stamp 12 can have any surface design in order to take account of other shaping options when calibrating.
  • the volumes of the recesses 16 essentially correspond to the volumes of the material stores 8 or the projections 9.
  • the volumes of the material stores 8 are preferably a little larger than the volumes of the recesses 16 assigned to them in order to ensure that they are filled securely.
  • Figures 7 to 11 show the pressing device 1 in detail. It consists of the aforementioned lower punch 12, a die 14 with a lateral receptacle or guide 21, an upper punch 10 and a clamping ring 11.
  • the die 14 is divided into two or more jaws 15, which are essentially movable transversely to the pressing direction 19 (FIGS. 8, 8a). As FIGS. 8 and 8a illustrate, a spring 18 is clamped between adjacent jaws 15 and forces the jaws 15 apart. The die 14 can thereby open automatically.
  • the invention extends to other opening mechanisms.
  • a clamping ring 11 is provided, which is elastic on the holding plate 23 of the upper punch 10, e.g. is attached via springs and encloses this, 10, on all sides.
  • the jaws 15 are in turn held movably in a lateral receptacle 21.
  • the clamping ring 11 has an internal conical clamping surface 17 which widens towards the die 14.
  • the die 14 or its jaws 15 in turn have a jacket 24 designed as a counter-cone.
  • the lower punch 12 protrudes through the lower, guided in the lateral receptacle 21 and movable in this receptacle 26 and is guided centrally in the die 14.
  • the recess 16 continues downward and, with its lateral boundaries, serves as a guide surface for the lower punch 12.
  • the recess 16 can have the shape of a straight or curved groove or some other suitable shape such as an annular groove.
  • a plurality of recesses 16 can also be arranged distributed around the press axis 19. The recesses 16 are located on the inside of the die jaws 15.
  • the blank 2 When calibrating, the blank 2 is brought to the desired final dimensions of the pressed part 7 and is also compacted substantially uniformly.
  • FIG. 7 shows the starting position of the opened pressing device 1.
  • the blank 2 is placed in the opened die 14.
  • the embodiment shown corresponds to FIG. 3.
  • the stamp 10 is raised again with the clamping ring 11 in order to demold.
  • the jaws 15 of the die 14 automatically open due to the pressure of the springs 18 (FIGS. 8, 8a) and release the compact 7.
  • the compact can be ejected by lifting the lower punch 12. It can also be removed from the die 14 in other ways.
  • a guerlaufischer slide should be installed, which presses on the blank and presses in the undercut.
  • the punches 10, 12 and the die 14 can have a different shape from the exemplary embodiment shown.
  • both the shoulder and the back shoulder of an undercut can be molded during calibration.
  • the upper punch 10 can be designed in a similar manner to the lower punch 12, the die 14 also having lateral recesses 16 in the upper region.
  • the closing mechanisms for the die segments 15 can be different.
  • eccentric or toggle lever systems can be used or hydraulic cylinders can perform the locking function.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Powder Metallurgy (AREA)

Abstract

Pressed metal powder part, esp. sintered part, with one or more re-entrant grooves, in which the re-entrant groove is formed by an additional finish pressing operation on a preformed compact. A mfg. process and equipment for the above are also claimed. <IMAGE>

Description

Die Erfindung betrifft ein Preßteil aus Metallpulver, insbesondere ein Sinterteil mit mindestens einer quer zur Preßrichtung liegenden Hinterschneidung, nebst Verfahren und Vorrichtung zu seiner Herstellung mit den Merkmalen im Oberbegriff der nebengeordneten Ansprüche.The invention relates to a pressed part made of metal powder, in particular a sintered part with at least one undercut lying transversely to the pressing direction, together with a method and device for its production with the features in the preamble of the independent claims.

Aus der DE-OS 37 34 002 ist ein Sintermetallkörper bebekannt, der quer zur Preßrichtung liegende Hinterschneidungen aufweist. Um die Hinterschneidungen zu bilden, ist der Sintermetallkörper mehrteilig aufgebaut. Die einzelnen geformten Teile werden zu einem Bauteil zusammengesteckt und dann durch Aufbringen einer Magnetitschicht auf ihre Oberflächen stoffschlüssig miteinander verbunden. Diese Vorgehensweise erfordert durch die Mehrteiligkeit des Sintermetallkörpers einen gewissen Bau- und Verfahrensaufwand. Die Hinterschneidungen können auch durch spanende Bearbeitung nachträglich in den Sintermetallkörper eingebracht werden. Ferner wird die Möglichkeit angesprochen, die Einzelteile eines mehrteiligen Sintermetallkörpers durch Schweißen oder Löten zu vereinigen. Diese Techniken bedeuten ebenfalls einen erhöhten Bau- und Verfahrensaufwand, der sich in den Kosten und in der Wirtschaftlichkeit des herzustellenden Preßteiles nachteilig niederschlägt.From DE-OS 37 34 002 a sintered metal body is known which has undercuts lying transverse to the pressing direction. In order to form the undercuts, the sintered metal body is constructed in several parts. The individual shaped parts are put together to form a component and then bonded to one another by applying a magnetite layer to their surfaces. Due to the multi-part nature of the sintered metal body, this procedure requires a certain amount of construction and process effort. The undercuts can also be subsequently machined into the sintered metal body. The possibility of combining the individual parts of a multi-part sintered metal body by welding or soldering is also addressed. These techniques also mean an increased construction and process effort, which is reflected in the cost and in the economy of the pressed part to be produced.

Es ist Aufgabe der vorliegenden Erfindung, ein Preßteil, insbesondere ein pulvermetallurgisch hergestelltes Sinterteil aufzuzeigen, das die vorbeschriebenen Nachteile nicht hat sowie ein Herstellungsverfahren und eine Vorrichtung anzugeben, mit Hilfe derer Hinterschneidungen aufweisende Preß- und Sinterteile aus Metallpulver einfacher und wirtschaftlicher als bisher produziert werden können.It is an object of the present invention to show a pressed part, in particular a powder metallurgically produced sintered part, which does not have the disadvantages described above, and to specify a production method and a device with the aid of which undercuts, pressed and sintered parts made of metal powder can be produced more easily and economically than before .

Die Erfindung löst diese Aufgabe mit den Merkmalen in den Sach-, Verfahrens- und Vorrichtungsansprüchen, die hiermit in die Beschreibung eingefügt werden.The invention solves this problem with the features in the factual, method and device claims, which are hereby inserted into the description.

Das auf pulvermetallurgischem Wege hergestellte erfindungsgemäße Preß- oder Sinterteil zeichnet sich durch einstückig angeformte Hinterschneidungen aus, d.h., die Hinterschneidungen werden bei einem Preßvorgang, vorzugsweise beim Kalibrieren, an einen vorgepreßten einteiligen Rohling angeformt. Bei einem Sinterteil liegt der Rohling bereits in gesintertem Zustand vor. Die vorgenannte Verfahrensweise läßt ein Zusammensetzen aus vorher separat gepreßten Einzelteilen oder/und aufwendige Nachbearbeitungen entfallen. Durch die Einstückigkeit des Rohlings werden Toleranzprobleme, die z.B. durch Addition von an zu fügenden Teilen vorhandenen Über- oder Untermaßen entstehen, vermieden. Außerdem läßt sich das erfindungsgemäße Verfahren schneller, einfacher und kostengünstiger durchführen.The pressed or sintered part according to the invention, which is produced by powder metallurgy, is characterized by undercuts formed in one piece, i.e. the undercuts are formed on a pre-pressed one-piece blank during a pressing process, preferably during calibration. In the case of a sintered part, the blank is already in the sintered state. The aforementioned procedure eliminates the need to assemble previously separately pressed individual parts and / or costly post-processing. The one-piece design of the blank eliminates tolerance problems, e.g. caused by adding existing over- or undersizes to parts to be joined. In addition, the method according to the invention can be carried out more quickly, simply and cost-effectively.

Für die Anformung der Hinterschneidungen die beim letzten Preß- oder Kalibriervorgang erfolgt, gibt es verschiedene Möglichkeiten. In der bevorzugten Ausführungsform werden die Hinterschneidungen an den Rohling beim Kalibrieren durch Materialverschiebung angeformt. Dabei kann zugleich eine Verdichtung des Rohlings stattfinden. Es kann z.B. auch ein Stempel oder Schieber quer auf den Rohling drücken und die Hinterschneidung einpressen.There are various options for the shaping of the undercuts that take place during the last pressing or calibration process. In the preferred embodiment, the undercuts are formed on the blank during calibration by material displacement. At the same time, the blank can be compacted. For example, also press a punch or slide across the blank and press in the undercut.

In der bevorzugten Ausführungsform wird der Boden der Hinterschneidungen jedoch durch die Grundform des vorhandenen Rohlings gebildet und beim Kalibrieren für jede Hinterschneidung lediglich eine vorstehende Schulter angeformt. Vorzugsweise geschieht dies, indem ein im Rohling vorhandener Materialvorrat verschoben wird, wodurch eine vorstehende Schulter für die Hinterscheidung angeformt wird.In the preferred embodiment, however, the base of the undercuts is formed by the basic shape of the blank present and, during calibration, only one protruding shoulder is molded on for each undercut. This is preferably done by shifting a material supply in the blank, which forms a protruding shoulder for the differentiation.

Die Materialverschiebung erfolgt vorzugsweise durch einen beweglichen Stempel, der das an entsprechender Stelle im Rohling vorhandene Material quer zur Preßrichtung in eine an einer Matrize befindliche seitliche Ausnehmung verdrängt und dadurch die vorerwähnte Schulter anformt. Der Materialvorrat ist volumenmäßig mindestens gleich groß wie die Ausnehmung und beide, der Materialvorrat und die Ausnehmung sind benachbart angeordnet. Vorzugsweise ist der Materialvorrat volumenmäßig etwas größer als die Ausnehmung.The material is shifted preferably by means of a movable punch which displaces the material present at a corresponding point in the blank transversely to the pressing direction into a lateral recess located on a die and thereby forms the aforementioned shoulder. The volume of material is at least the same volume as the recess and both, the material supply and the recess are arranged adjacent. The volume of material is preferably somewhat larger in volume than the recess.

Nach einer bevorzugten Variante befindet sich der Materialvorrat in Form einer Erhebung an der Oberfläche des Rohlings in Nachbarschaft der später die Schulter bildenden, in der Matrize befindlichen Ausnehmung. Nach einer anderen bevorzugten Variante befindet sich der Materialvorrat im Rohling und wird beim Pressen oder Kalibrieren durch Eindringen eines am Preßstempel befindlichen Vorsatzes in den Rohling verschoben. Das Volumen des Vorsatzes ist mindestens so groß wie das der später die Schulter formenden Ausnehmung.According to a preferred variant, the material supply is in the form of an elevation on the surface of the blank in the vicinity of the recess in the die which later forms the shoulder. According to another preferred variant, the material supply is in the blank and is pushed into the blank during pressing or calibration by penetration of an attachment located on the press ram. The volume of the attachment is at least as large as that of the recess that later forms the shoulder.

Das erfindungsgemäße Verfahren läßt sich in einer konventionellen Preßvorrichtung durchführen. Es muß jedoch eine der Formungsaufgabe angepaßte Matrize verwendet werden. Diese hat zwei oder mehr bewegliche Backen oder Segmente, von denen mindestens einer/eins an der Preßfläche eine Ausnehmung aufweist, die in Form und Volumen der später die Hinterschneidung überkragenden Schulter entspricht. Zum Entformen des fertigen und kalibrierten Preßteiles kann die Matrize geöffnet werden, wodurch auch die Hinterschneidung freigegeben wird.The method according to the invention can be carried out in a conventional pressing device. However, a die adapted to the molding task must be used. This has two or more movable jaws or segments, of which at least one / one has a recess on the pressing surface which corresponds in shape and volume to the shoulder which later projects beyond the undercut. The mold can be opened to remove the finished and calibrated pressed part, which also releases the undercut.

Im folgenden wird das erfindungsgemäße Verfahren in seinem gesamten Ablauf anhand der Variante, bei der sich das Materialreservoir in Form einer Erhebung an der Oberfläche des Rohlings befindet, beschrieben. Zunächst wird auf pulvermetallurgischem Wege ein Vorproduktkörper hergestellt, bei dem sich auf einer Fläche, die der späteren Hinterschneidung benachbart ist und die quer zur Preßrichtung beim Kalibrieren liegt, ein Materialreservoir befindet, dessen Volumen mindestens dem Volumen entspricht, das im fertigen Sinterkörper die die Hinterschneidung überragende und begrenzende Schulter einnimmt. Danach wird der Vorproduktkörper in eine aus mindestens zwei bewegbaren Segmenten bestehende Matrize, die sich durch Auseinanderfahren der Segmente in geöffnetem Zustand befindet, eingelegt. Diese Matrize hat an ihrer Innenwand mindestens eine Ausnehmung, die der vorgesehenen Form der mindestens einen, im fertigen Sintermetallteil die Hinterschneidung überragenden und begrenzenden Schulter äquivalent ist. Der Vorproduktkörper wird so in die Matrize eingelegt, daß sich sein das Materialreservoir tragender Bereich an der Stelle befindet, an der in der Matrizeninnenwand die entsprechende Ausnehmung für die Formung der die Hinterschneidung überragenden Schulter ist. Sodann wird die Matrize mit dem Vorproduktkörper in einer mindestens einen Preßstempel aufweisenden Gesenkpresse in Preßposition gebracht, die Matrize mittels einer z.B. hydraulisch oder mechanisch wirkenden Schließvorrichtung durch Aneinanderpressen der Segmente auf Kalibriermaß geschlossen und der Vorproduktkörper mit einem Preßstempel unter Anwendung eines solchen Drucks kalibriert, daß das an ihm oder in ihm befindliche Materialreservoir durch Fließvorgänge in die in der Matrizenwand befindliche Ausnehmung umgelagert wird und damit die die Hinterschneidung überragende und begrenzende Ausbuchtung entsteht. Nach diesem Preßvorgang wird der Preßstempel aus der Matrize entfernt, die die Matrizensegmente zusammenspannende Schließeinrichtung entlastet bzw. entfernt, es werden die Matrizensegmente in Öffnungsstellung nach außen bewegt und es wird das fertige Preßteil entnommen.The entire sequence of the method according to the invention is described below with the aid of the variant in which the material reservoir is located in the form of an elevation on the surface of the blank. First, a pre-product body is produced by powder metallurgy, in which there is a material reservoir on a surface that is adjacent to the later undercut and that is transverse to the pressing direction during calibration, the volume of which corresponds at least to the volume that in the finished sintered body exceeds the undercut and occupies a limiting shoulder. The pre-product body is then inserted into a die which consists of at least two movable segments and which is in the open state when the segments are moved apart. This die has at least one recess on its inner wall which is equivalent to the intended shape of the at least one shoulder which projects beyond and delimits the undercut in the finished sintered metal part. The pre-product body is inserted into the die in such a way that its area carrying the material reservoir is located at the point at which the corresponding recess in the inner wall of the die for the formation of the shoulder projecting beyond the undercut. The die is then brought into the pressing position with the pre-product body in a die press having at least one press die, the die is closed to a calibration dimension by pressing the segments together, for example by means of a hydraulically or mechanically acting closing device, and the pre-product body is calibrated with a press die using such a pressure that this on it or in the material reservoir located in it is rearranged by flow processes into the recess located in the die wall, thus creating the bulge which is superior and delimiting the undercut. To This pressing process removes the press ram from the die, which relieves or removes the closing device spanning the die segments, the die segments are moved outwards in the open position and the finished press part is removed.

In den Unteransprüchen, die auch als Teil der Beschreibung angesehen werden, sind vorteilhafte Ausgestaltungen der Preßvorrichtung beschrieben. Dies betrifft zum einen eine Matrize, die zwei oder mehr quer zur Preßrichtung bewegliche Backen oder Segmente aufweist und zum anderen einen konischen Spannring, der für einen automatischen und festen Verschluß der beweglichen Backen der Matrize beim Kalibrieren sorgt. Ferner sind unterschiedlich gestaltete Preßstempel vorgesehen, um gezielte Formgebungsvarianten am fertigen Preßteil vornehmen zu können.Advantageous configurations of the pressing device are described in the subclaims, which are also considered part of the description. This relates on the one hand to a die which has two or more jaws or segments movable transversely to the pressing direction and on the other hand to a conical clamping ring which ensures automatic and firm closure of the movable jaws of the die during calibration. Furthermore, differently designed press rams are provided in order to be able to carry out specific shaping variants on the finished pressed part.

Das Preßteil bzw. der Rohling kann aus einem beliebigen geeigneten Metallpulver bestehen. Es hat sich als vorteilhaft erwiesen, wenn das Rohlingsmaterial eine Bruchdehnung von mehr als 2% aufweist, vorzugsweise mehr als 10%. Geeignete Materialien sind z.B. SINT D35 (phosphorhaltige Stähle), SINT D40 (Rostfreistahl) etc..The pressed part or the blank can consist of any suitable metal powder. It has proven to be advantageous if the blank material has an elongation at break of more than 2%, preferably more than 10%. Suitable materials are e.g. SINT D35 (phosphorus-containing steels), SINT D40 (stainless steel) etc.

Die Erfindung ist in den Zeichnungen beispielhaft und schematisch dargestellt. Im einzelnen zeigen:

Figur 1 und 2 :
das fertige Preß- oder Sinterteil mit Hinterschneidungen in Draufsicht und im Längsschnitt,
Figur 3 und 4 :
den Verformungsgang eines Rohlings beim Ankalibrieren der Hinterschneidung im Halbschnitt längs,
Figur 5 und 6 :
eine Variante zu Figur 3 und 4 und
Figur 7 bis 11:
die Preßvorrichtung in verschiedenen Arbeitsstellungen und Ansichten.
The invention is illustrated by way of example and schematically in the drawings. In detail show:
Figure 1 and 2:
the finished pressed or sintered part with undercuts in top view and in longitudinal section,
Figures 3 and 4:
the deformation path of a blank when calibrating the undercut in half-cut lengthways,
Figure 5 and 6:
a variant of Figure 3 and 4 and
Figure 7 to 11:
the pressing device in different working positions and views.

Figur 1 und 2 zeigen ein fertiges Preßteil 7 aus Metallpulver, vorzugsweise in Form eines Sinterteiles. Es besteht vorzugsweise aus einem legierten Stahl, kann aber auch eine beliebige andere geeignete metallische Zusammensetzung haben.Figures 1 and 2 show a finished pressed part 7 made of metal powder, preferably in the form of a sintered part. It is preferably made of an alloy steel, but can also have any other suitable metallic composition.

Das fertige Preß- oder Sinterteil besteht aus einem Metall, das eine Bruchdehnung von mehr als 2%, vorzugsweise mehr als 10% aufweist. Geeignete Materialien sind z.B. SINT D35 (phosphorhaltige Stähle) oder SINT D40 (rostfreie Stähle).The finished pressed or sintered part consists of a metal which has an elongation at break of more than 2%, preferably more than 10%. Suitable materials are e.g. SINT D35 (phosphorus-containing steels) or SINT D40 (stainless steels).

Das fertige Preßteil 7 besitzt mindestens eine quer zur Preßrichtung liegende Hinterschneidung 3. Im gezeigten Ausführungsbeispiel handelt es sich um zwei um 180° einander gegenüberliegende Hinterschneidungen 3 in Form von querlaufenden Nuten oder auch Mulden. Figur 2 verdeutlicht die Ausbildung im Längsschnitt. Die Hinterschneidung 3 besitzt einen Boden 4 und eine vorspringende Schulter 5. Die Gegenschulter wird hier durch eine verbreiterte Kopfplatte 6 gebildet.The finished press part 7 has at least one undercut 3 lying transversely to the pressing direction. In the exemplary embodiment shown there are two undercuts 3 lying opposite one another in the form of transverse grooves or troughs. Figure 2 illustrates the training in longitudinal section. The undercut 3 has a base 4 and a projecting shoulder 5. The counter shoulder is formed here by a widened head plate 6.

Das Preßteil 7 kann in beliebig anderer Weise ausgebildet sein. Es kann auch nur eine Hinterschneidung 3 oder auch drei und mehr Hinterschneidungen 3 oder auch eine Ringnut aufweisen, die zudem beliebig am Preßteil 7 verteilt sein können/kann.The pressing part 7 can be designed in any other way. There can also be only one undercut 3 or even three or more undercuts 3 or an annular groove have, which can also be distributed as desired on the pressing part 7.

Das Fertigteil 7 erhält die Hinterschneidungen 3 beim Kalibrieren eines vorgepreßten, im Falle eines Sinterteils eines vorgepreßten und gesinterten, aus nur einem Teil bestehenden Rohlings 2 durch Anformen. Wie die Figuren 3 bis 6 verdeutlichen, werden dabei die Schultern 5 durch Materialverschiebung angeformt. Der Kalibriervorgang findet in einer Preßvorrichtung 1 statt, die nachfolgend unter Bezugnahme auf Figur 7 bis 11 näher beschrieben und dargestellt ist.The finished part 7 receives the undercuts 3 when calibrating a pre-pressed, in the case of a sintered part a pre-pressed and sintered blank 2 consisting of only one part by molding. As shown in FIGS. 3 to 6, the shoulders 5 are formed by shifting the material. The calibration process takes place in a press device 1, which is described and illustrated in more detail below with reference to FIGS. 7 to 11.

Der Rohling 2 besitzt eine einfache, durch Pressen von gegebenenfalls mit einem Binder versehenen Pulvern und vorzugsweise nachfolgendes Sintern leicht herzustellende Form. Im gezeigten Ausführungsbeispiel hat er bereits die Kopfplatte 6 und einen glatten Schaft oder Zapfen 22, der den in Figur 1 gezeigten, in etwa tonnenförmigen Querschnitt aufweist. Der Rohling 2 hat noch keine fertige Hinterschneidung 3 quer zu seiner Preßrichtung. Die Seitenwände des Schaftes oder Zapfens 22 bilden allerdings bereits die späteren Böden 4 der in Fig. 4 wiedergegebenen Hinterschneidungen 3.The blank 2 has a simple shape which can be easily produced by pressing powders optionally provided with a binder and preferably subsequent sintering. In the exemplary embodiment shown, it already has the top plate 6 and a smooth shank or pin 22 which has the approximately barrel-shaped cross section shown in FIG. The blank 2 does not yet have a finished undercut 3 transverse to its pressing direction. The side walls of the shaft or pin 22, however, already form the later bases 4 of the undercuts 3 shown in FIG. 4.

Wie die Figuren 3 bis 6 verdeutlichen, hat der Rohling 2 Materialvorräte 8, die beim Kalibrieren verschoben werden und die dadurch die neuen Schultern 5 bilden.As FIGS. 3 to 6 illustrate, the blank 2 has material stocks 8 which are shifted during calibration and which thereby form the new shoulders 5.

In Figur 3 bestehen die Materialvorräte 8 aus in Preßrichtung 19 abstehenden Vorsprüngen 9. Die Vorsprünge 9 werden in der Preßvorrichtung 1 durch einen Stempel 12 flachgedrückt, wobei die Materialvorräte quer zur Preßrichtung 19 umgelenkt und in seitliche Ausnehmungen 16 an einer Matrize 14 verdrängt werden. Die Form der Ausnehmungen 16 entsprechen den zu bildenden Schultern 5. Der Stempel 12 formt die Oberflächen der Schultern 5. Figur 4 zeigt die Gestalt des fertigen Preßteiles mit den Hinterschneidungen 3 und den angeformten Schultern 5.In FIG. 3, the material stocks 8 consist of projections 9 protruding in the pressing direction 19. The projections 9 are pressed flat in the pressing device 1 by a punch 12, the material stocks being deflected transversely to the pressing direction 19 and displaced into lateral recesses 16 on a die 14. The shape of the recesses 16 correspond to the shoulders 5 to be formed. The stamp 12 forms the surfaces of the shoulders 5. FIG. 4 shows the shape of the finished pressed part with the undercuts 3 and the molded shoulders 5.

Im Ausführungsbeispiel von Figur 5 hat der Rohling 2 keinen Vorsprung 9. Die Materialvorräte sind hier in die Grundform des Rohlings integriert und deshalb nicht gesondert dargestellt. Der Stempel 12 besitzt an der Oberseite zwei höckerartige Profilierungen 13, die beim Kalibrieren im fertigen Preßteil 7 eine Mulde 20 hinterlassen. Durch die schrägen Flanken der Profilierungen 13 wird das Material des Rohlings beim Kalibrieren in den betreffenden Randbereichen des Zapfens zur Seite in die Ausnehmungen 16 verdrängt. Dadurch ergibt sich die in Figur 6 gezeigte vom Preßwerkzeug eingeschlossene Endform des Preßteils 7.In the exemplary embodiment in FIG. 5, the blank 2 has no protrusion 9. The material stocks are integrated into the basic shape of the blank and are therefore not shown separately. The punch 12 has two bump-like profiles 13 on the upper side, which leave a depression 20 in the finished pressed part 7 during calibration. Due to the oblique flanks of the profiles 13, the material of the blank is displaced to the side into the recesses 16 during calibration in the relevant edge regions of the journal. This results in the final shape of the press part 7 shown in FIG. 6 which is enclosed by the press tool.

Zwischen den gezeigten Ausführungsbeispielen sind Mischformen und Abwandlungen möglich. Der untere Stempel 12 kann auch in der Ausführungsform von Figur 3 eine in Preßrichtung 19 vorstehende Profilierung aufweisen. Ansonsten kann der Stempel 12 eine beliebige Oberflächengestaltung besitzen, um anderen Formgebungsmöglichkeiten beim Kalibrieren Rechnung zu tragen.Mixed forms and modifications are possible between the exemplary embodiments shown. In the embodiment of FIG. 3, the lower punch 12 can also have a profile protruding in the pressing direction 19. Otherwise, the stamp 12 can have any surface design in order to take account of other shaping options when calibrating.

Die Volumina der Ausnehmungen 16 entsprechen im wesentlichen den Volumina der Materialvorräte 8 bzw. der Vorsprünge 9. Vorzugsweise sind die Volumina der Materialvorräte 8 ein bischen größer als die Volumina der ihnen jeweils zugeordneten Ausnehmungen 16, um deren, 16, sichere Füllung zu gewährleisten.The volumes of the recesses 16 essentially correspond to the volumes of the material stores 8 or the projections 9. The volumes of the material stores 8 are preferably a little larger than the volumes of the recesses 16 assigned to them in order to ensure that they are filled securely.

Die Figuren 7 bis 11 zeigen die Preßvorrichtung 1 im einzelnen. Sie besteht aus dem vorerwähnten Unterstempel 12, einer Matrize 14 mit einer seitlichen Aufnahme oder Führung 21, einem Oberstempel 10 und einem Spannring 11.Figures 7 to 11 show the pressing device 1 in detail. It consists of the aforementioned lower punch 12, a die 14 with a lateral receptacle or guide 21, an upper punch 10 and a clamping ring 11.

Um das fertige Preßteil 7 nach dem Kalibrieren entformen zu können (Fig. 11), ist die Matrize 14 in zwei oder mehr Backen 15 geteilt, die im wesentlichen quer zur Preßrichtung 19 beweglich sind (Fig. 8, 8a). Wie die Figuren 8 und 8a verdeutlichen, ist zwischen benachbarte Backen 15 jeweils eine Feder 18 eingespannt, die die Backen 15 auseinanderdrängt. Die Matrize 14 kann sich dadurch automatisch öffnen. Die Erfindung erstreckt sich auch auf andere Öffnungsmechanismen.In order to be able to demold the finished pressed part 7 after calibration (FIG. 11), the die 14 is divided into two or more jaws 15, which are essentially movable transversely to the pressing direction 19 (FIGS. 8, 8a). As FIGS. 8 and 8a illustrate, a spring 18 is clamped between adjacent jaws 15 and forces the jaws 15 apart. The die 14 can thereby open automatically. The invention extends to other opening mechanisms.

Zum Schließen der Matrize 14 und zum Anpressen ihrer Backen 15 ist ein Spannring 11 vorgesehen, der an der Halteplatte 23 des Oberstempels 10 elastisch, z.B. über Federn, befestigt ist und diesen, 10, allseits umumschließt. Die Backen 15 sind ihrerseits in einer seitlichen Aufnahme 21 beweglich gehalten. Der Spannring 11 hat eine innenliegende konische Spannfläche 17, die sich zur Matrize 14 hin erweitert. Die Matrize 14 bzw. deren Backen 15 haben ihrerseits einen als Gegenkonus ausgegebildeten Mantel 24. Wenn der Oberstempel 10 mit dem Spannring 11 gemäß Figuren 7 bis 10 abgesenkt wird, übergreift der Spannring 11 die Backen 15 und preßt diese radial zusammen.To close the die 14 and to press its jaws 15, a clamping ring 11 is provided, which is elastic on the holding plate 23 of the upper punch 10, e.g. is attached via springs and encloses this, 10, on all sides. The jaws 15 are in turn held movably in a lateral receptacle 21. The clamping ring 11 has an internal conical clamping surface 17 which widens towards the die 14. The die 14 or its jaws 15 in turn have a jacket 24 designed as a counter-cone. When the upper punch 10 is lowered with the clamping ring 11 according to FIGS. 7 to 10, the clamping ring 11 engages over the jaws 15 and presses them radially together.

Der Unterstempel 12 ragt durch die untere, in der seitlichen Aufnahme 21 geführte und in dieser bewegliche Aufnahme 26 und ist zentrisch in der Matrize 14 geführt. Wie die Figuren 3 bis 6 verdeutlichen, setzt sich die Ausnehmung 16 nach unten fort und dient mit ihren seitlichen Begrenzungen als Führungsfläche für den Unterstempel 12. Je nach der gewünschten Schulterform kann die Ausnehmung 16 die Form einer geraden oder gebogenen Nut oder eine sonstige geeignete Form wie beispielsweise eine Ringnut haben. Es können auch mehrere Ausnehmungen 16 um die Preßachse 19 herum verteilt angeordnet sein. Die Ausnehmungen 16 befinden sich an der Innenseite der Matrizenbacken 15.The lower punch 12 protrudes through the lower, guided in the lateral receptacle 21 and movable in this receptacle 26 and is guided centrally in the die 14. As FIGS. 3 to 6 illustrate, the recess 16 continues downward and, with its lateral boundaries, serves as a guide surface for the lower punch 12. Depending on the desired shoulder shape, the recess 16 can have the shape of a straight or curved groove or some other suitable shape such as an annular groove. A plurality of recesses 16 can also be arranged distributed around the press axis 19. The recesses 16 are located on the inside of the die jaws 15.

Beim Kalibrieren wird der Rohling 2 auf die gewünschten Endmaße des Preßteiles 7 gebracht und dabei auch im wesentlichen gleichmäßig verdichtet.When calibrating, the blank 2 is brought to the desired final dimensions of the pressed part 7 and is also compacted substantially uniformly.

Figur 7 zeigt die Ausgangsstellung der geöffneten Preßvorrichtung 1. Der Rohling 2 wird in die geöffnete Matrize 14 eingelegt. Die gezeigte Ausführungsform entspricht Figur 3.FIG. 7 shows the starting position of the opened pressing device 1. The blank 2 is placed in the opened die 14. The embodiment shown corresponds to FIG. 3.

Anschließend (Fig. 9) wird der Oberstempel 10 mit dem Spannring 11 soweit abgesenkt, daß die Matrize 14 in der vorbeschriebenen Weise geschlossen wird. Sodann wird der Oberstempel 10 mittels seiner Halteplatte 23 unter teilweisem Zusammendrücken der zwischen der Halteplatte 23 und dem Spannring 11 befindlichen Federn 25 auf die Kopfplatte 6 des Rohlings 2 gefahren, wobei der auf die Segmente 15 der Matrize 14 wirkende Schließdruck weiter erhöht wird. Beim nun folgenden Kalibrierungsprozeß (Fig. 10) wird unter weiterer Erhöhung der Kalibrierkraft die gesamte aus Halteplatte 23 für den Oberstempel, Oberstempel 10, Spannring 11, Matrize 14 und unterer Aufnahme 26 bestehende Anordnung gegen den stehenden Unterstempel 12 abgesenkt. Die seitliche Aufnahme oder Führung 21 für die Matrize 14 und den Spannring 11 bleibt dabei ortsfest. Bei diesem Vorgang werden die Materialvorräte 8 in die Ausnehmungen 16 (Fig. 9) verdrängt, die Schultern 5 der Hinterschneidungen 3 angeformt und der Rohling auf die Endmaße des Fertigteils 7 kalibriert.Then (Fig. 9) the upper punch 10 is lowered with the clamping ring 11 so far that the die 14 is closed in the manner described above. Then the upper punch 10 is moved by means of its holding plate 23 with partial compression of the springs 25 located between the holding plate 23 and the clamping ring 11 onto the head plate 6 of the blank 2, the closing pressure acting on the segments 15 of the die 14 being further increased. In the following calibration process (FIG. 10), the entire arrangement consisting of holding plate 23 for the upper punch, upper punch 10, clamping ring 11, die 14 and lower receptacle 26 is lowered against the standing lower punch 12 while the calibration force is increased further. The lateral receptacle or guide 21 for the die 14 and the clamping ring 11 remains stationary. In this process, the material stocks 8 are displaced into the recesses 16 (FIG. 9), the shoulders 5 of the undercuts 3 are formed and the Blank calibrated to the final dimensions of the finished part 7.

Im letzten Schritt gemäß Figur 11 wird zum Entformen der Stempel 10 mit dem Spannring 11 wieder angehoben. Hierdurch öffnen sich durch den Druck der Federn 18 (Fig. 8, 8a) automatisch die Backen 15 der Matrize 14 und geben den Preßling 7 frei. Durch Anheben des Unterstempels 12 kann der Preßling ausgestoßen werden. Er kann auch auf andere Weise aus der Matrize 14 entfernt werden.In the last step according to FIG. 11, the stamp 10 is raised again with the clamping ring 11 in order to demold. As a result, the jaws 15 of the die 14 automatically open due to the pressure of the springs 18 (FIGS. 8, 8a) and release the compact 7. The compact can be ejected by lifting the lower punch 12. It can also be removed from the die 14 in other ways.

Abwandlungen der beschriebenen Ausführungsbeispiele sind in verschiedener Weise möglich. In die Matrize kann z.B. ein guerlaufender Schieber eingebaut sein, der auf den Rohling drückt und die Hinterschneidung einpreßt. Ferner können die Stempel 10, 12 und die Matrize 14 gegenüber dem gezeigten Ausführungsbeispiel eine abweichende Form haben. Zum Beispiel können beim Kalibrieren sowohl die Schulter als auch die Gegenschulter einer Hinterschneidung angeformt werden. Zu diesem Zweck kann der Oberstempel 10 in ähnlicher Weise wie der Unterstempel 12 ausgebildet sein, wobei die Matrize 14 auch im oberen Bereich seitliche Ausnehmungen 16 aufweist.Modifications to the described exemplary embodiments are possible in various ways. For example, a guerlaufischer slide should be installed, which presses on the blank and presses in the undercut. Furthermore, the punches 10, 12 and the die 14 can have a different shape from the exemplary embodiment shown. For example, both the shoulder and the back shoulder of an undercut can be molded during calibration. For this purpose, the upper punch 10 can be designed in a similar manner to the lower punch 12, the die 14 also having lateral recesses 16 in the upper region.

Desweiteren können die Schließmechanismen für die Matrizensegmente 15 unterschiedlich sein. Beispielsweise können Exzenter- oder Kniehebelsysteme zum Einsatz kommen oder Hydraulikzylinder die Schließfunktion erfüllen.Furthermore, the closing mechanisms for the die segments 15 can be different. For example, eccentric or toggle lever systems can be used or hydraulic cylinders can perform the locking function.

BezugszeichenlisteReference list

11
PreßvorrichtungPressing device
22nd
Rohlingblank
33rd
HinterschneidungUndercut
44th
Bodenground
55
Schultershoulder
66
Gegenschulter, KopfplatteCounter shoulder, headstock
77
Preßteil, Sinterteil, FertigteilPressed part, sintered part, finished part
88th
MaterialvorratMaterial stock
99
Vorsprunghead Start
1010th
Stempel, OberstempelStamp, upper stamp
1111
SpannringTension ring
1212th
Stempel, UnterstempelStamp, lower stamp
1313
ProfilierungProfiling
1414
Matrizedie
1515
Backe, SegmentCheek, segment
1616
AusnehmungRecess
1717th
SpannflächeClamping surface
1818th
Federfeather
1919th
PreßrichtungPressing direction
2020th
Muldetrough
2121
seitliche Aufnahme, Führung für 11side mount, guide for 11
2222
Schaft oder ZapfenShaft or tenon
2323
Halteplatte für OberstempelHolding plate for upper stamp
2424th
Außenmantel der Matrize (Gegenkonus)Outer jacket of the die (counter cone)
2525th
Federn zwischen 23 und 11Feathers between 23 and 11
2626
untere Aufnahme in der Preßvorrichtung 1lower receptacle in the pressing device 1

Claims (15)

Preßteil aus Metallpulver, insbesondere Sinterteil, mit mindestens einer quer zur Preßrichtung liegenden Hinterschneidung,
dadurch gekennzeichnet, daß
die Hinterschneidung (3) durch Umformen eines einstückigen gepreßten Rohlings zum Fertigteil durch einen zusätzlichen Preßvorgang angeformt ist.Pressed part made of metal powder, in particular sintered part, with at least one undercut lying transverse to the pressing direction,
characterized in that
the undercut (3) is formed by reshaping a one-piece pressed blank into the finished part by an additional pressing process. Preßteil, insbesondere Sinterteil aus Metallpulver nach Patentanspruch 1,
dadurch gekennzeichnet, daß
das Material, aus dem das Preßteil besteht, eine Bruchdehnung größer 2 %, vorzugsweise größer 10 % aufweist.Pressed part, in particular sintered part made of metal powder according to claim 1,
characterized in that
the material from which the pressed part is made has an elongation at break greater than 2%, preferably greater than 10%. Verfahren zur Herstellung von Preßteilen (7) aus Metallpulver mit mindestens einer quer zur Preßrichtung liegenden Hinterschneidung,
dadurch gekennzeichnet, daß
die Hinterschneidung (3) an einen vorgepreßten Rohling (2) beim Kalibrieren durch Materialverschiebung angeformt wird.Method for producing pressed parts (7) from metal powder with at least one undercut lying transversely to the pressing direction,
characterized in that
the undercut (3) is formed on a pre-pressed blank (2) during calibration by material displacement. Verfahren zur Herstellung von Sinterteilen (7) aus Metallpulver mit mindestens einer quer zur Preßrichtung liegenden Hinterschneidung,
dadurch gekennzeichnet, daß
die Hinterschneidung (3) an einen vorgepreßten und gesinterten Rohling (2) beim Kalibrieren durch Materialverschiebung angeformt wird.Method for producing sintered parts (7) from metal powder with at least one undercut lying transversely to the pressing direction,
characterized in that
the undercut (3) is formed on a pre-pressed and sintered blank (2) during calibration by material displacement. Verfahren nach Patentanspruch 3 oder 4,
dadurch gekennzeichnet, daß
der Boden (4) der Hinterschneidung (3) durch die Grundform des Rohlings (2) gebildet wird und daß beim Kalibrieren zumindest eine vorstehende Schulter (5) angeformt wird.Method according to claim 3 or 4,
characterized in that
the base (4) of the undercut (3) is formed by the basic shape of the blank (2) and that at least one protruding shoulder (5) is molded on during calibration. Verfahren nach Patentanspruch 3, 4 oder 5
dadurch gekennzeichnet, daß
beim Kalibrieren ein Stempel (12) das dazu bestimmte Material des Rohlings (2) zur Seite in eine Ausnehmung (16) verdrängt, die sich an der Innenwand einer Matrize (14) befindet.Method according to claim 3, 4 or 5
characterized in that
during calibration a stamp (12) displaces the intended material of the blank (2) to the side into a recess (16) which is located on the inner wall of a die (14). Verfahren nach Patentanspruch 3, 4, 5 oder 6
dadurch gekennzeichnet, daß
ein Rohling (2) mit einem Materialvorrat (8) hergestellt wird, der im Volumen im wesentlichen der Ausnehmung (16) entspricht und an diesem der Kalibriervorgang ausgeführt wird.Method according to claim 3, 4, 5 or 6
characterized in that
a blank (2) with a material supply (8) is produced which corresponds in volume to the recess (16) and on which the calibration process is carried out. Verfahren nach Patentanspruch 7,
dadurch gekennzeichnet, daß
der Materialvorrat (8) von einem in Preßrichtung (19) abstehenden Vorsprung (9) am Rohling (2) gebildet wird, und dieser Vorsprung (9) beim Kalibrieren des Rohlings (2) in diesen hinein- und in Folge von Verlagerungsvorgängen seitlich in die Ausnehmung (16) gepreßt wird.Method according to claim 7,
characterized in that
the material supply (8) is formed by a projection (9) protruding in the pressing direction (19) on the blank (2), and this projection (9) during calibration of the blank (2) into it and as a result of displacement processes laterally into it Recess (16) is pressed. Verfahren nach Patentanspruch 7,
dadurch gekennzeichnet, daß
der Materialvorrat (8) in der Grundform des Rohlings (2) vorhanden ist und beim Kalibrieren durch eine vorstehende Profilierung (13) am Stempel (12) unter Bildung einer Mulde (20) auf der dem Stempel (12) zugekehrten Seite des Rohlings (2) seitlich in die Ausnehmung (16) hinein verdrängt wird.Method according to claim 7,
characterized in that
the stock of material (8) is available in the basic shape of the blank (2) and when calibrated by a protruding profile (13) on the punch (12) below Formation of a trough (20) on the side of the blank (2) facing the punch (12) is laterally displaced into the recess (16). Vorrichtung zur Herstellung von Preßteilen aus Metallpulver, insbesondere Sinterteilen, mit mindestens einer quer zur Preßrichtung liegenden Hinterschneidung, bestehend aus einer Preßvorrichtung mit mindestens einem beweglichen Stempel und einer Matrize,
dadurch gekennzeichnet, daß
die Matrize (14) zwei oder mehr quer zur Preßrichtung (19) bewegliche Backen (15) aufweist, von denen mindestens eine an der Preßfläche eine Ausnehmung (16) aufweist.Device for producing pressed parts from metal powder, in particular sintered parts, with at least one undercut lying transversely to the pressing direction, consisting of a pressing device with at least one movable punch and a die,
characterized in that
the die (14) has two or more jaws (15) movable transversely to the pressing direction (19), at least one of which has a recess (16) on the pressing surface. Vorrichtung nach Patentanspruch 10,
dadurch gekennzeichnet, daß
die Preßvorrichtung (1) einen Spannring (11) aufweist, der beim Kalibrieren über die Matrize (14) greift, sie fest umschließt und die Backen (15) der Matrize (14) gegen den in der Matrize (14) herrschenden Innendruck aneinanderpreßt.Device according to claim 10,
characterized in that
the pressing device (1) has a clamping ring (11) which, when calibrating, reaches over the die (14), firmly encloses it and presses the jaws (15) of the die (14) against the internal pressure prevailing in the die (14). Vorrichtung nach Patentanspruch 11,
dadurch gekennzeichnet, daß
der Spannring (11) eine konische Spannfläche (17) und die Matrize (14) einen Gegenkonus (24) am Mantel aufweist.Device according to claim 11,
characterized in that
the clamping ring (11) has a conical clamping surface (17) and the die (14) has a counter cone (24) on the jacket. Vorrichtung nach Patentanspruch 11 oder 12,
dadurch gekennzeichnet, daß
der Spannring (11) an einem beweglichen Stempel (10) angeordnet ist.Device according to claim 11 or 12,
characterized in that
the clamping ring (11) is arranged on a movable punch (10). Vorrichtung nach Patentanspruch 10 oder einem der darauf folgenden,
dadurch gekennzeichnet, daß
der die Hinterschneidung (3) bildende Stempel (12) eine in Preßrichtung (19) vorstehende Profilierung (13) aufweist.Device according to claim 10 or one of the subsequent ones
characterized in that
the punch (12) forming the undercut (3) has a profile (13) protruding in the pressing direction (19). Vorrichtung nach Patentanspruch 14,
dadurch gekennzeichnet, daß
die Profilierung (13) mindestens das gleiche Volumen wie die zugehörige Ausnehmung (16) aufweist.Device according to claim 14,
characterized in that
the profiling (13) has at least the same volume as the associated recess (16).
EP95105492A 1994-05-20 1995-04-12 Article molded from metal powder and process and apparatus for preparing the same Expired - Lifetime EP0682999B1 (en)

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FR2942733A1 (en) * 2009-03-04 2010-09-10 Commissariat Energie Atomique PRESS TOOLS
CN103934455A (en) * 2014-03-13 2014-07-23 北京科技大学 Forming die and forming method for evaporating powder of alkali metal evaporator
CN104384513A (en) * 2014-12-09 2015-03-04 常熟市华德粉末冶金有限公司 Powder metallurgy side hole forming tool
DE102010061802B4 (en) * 2009-11-26 2015-10-22 Toyota Boshoku Kabushiki Kaisha Process for producing a separator for a fuel cell
EP3388227A1 (en) * 2017-04-13 2018-10-17 Seco Tools Ab Compacting device and method for producing a cutting insert green body by compacting a powder
AT522877B1 (en) * 2019-10-04 2021-03-15 Miba Sinter Austria Gmbh Bearing block

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EP1033193A4 (en) * 1998-09-18 2001-10-24 Injex Corp Method of forming undercut in metal powder injection-molded article and metal powder injection-molded article having undercut
US6444167B1 (en) 1998-09-18 2002-09-03 Injex Corporation Method of forming undercut in metal powder injection-molded article
EP1033193A1 (en) * 1998-09-18 2000-09-06 Injex Corporation Method of forming undercut in metal powder injection-molded article and metal powder injection-molded article having undercut
US6536305B2 (en) 2000-07-14 2003-03-25 Plansee Tizit Aktiengesellschaft Cutting plate and method of pressing a cutting plate
FR2942733A1 (en) * 2009-03-04 2010-09-10 Commissariat Energie Atomique PRESS TOOLS
DE102010061802B4 (en) * 2009-11-26 2015-10-22 Toyota Boshoku Kabushiki Kaisha Process for producing a separator for a fuel cell
CN103934455B (en) * 2014-03-13 2016-06-08 北京科技大学 The forming mould of a kind of alkali metal evaporator evaporation powder body and forming method
CN103934455A (en) * 2014-03-13 2014-07-23 北京科技大学 Forming die and forming method for evaporating powder of alkali metal evaporator
CN104384513A (en) * 2014-12-09 2015-03-04 常熟市华德粉末冶金有限公司 Powder metallurgy side hole forming tool
CN104384513B (en) * 2014-12-09 2016-05-11 常熟市华德粉末冶金有限公司 Powder metallurgy side opening shaping dies
EP3388227A1 (en) * 2017-04-13 2018-10-17 Seco Tools Ab Compacting device and method for producing a cutting insert green body by compacting a powder
WO2018189315A1 (en) * 2017-04-13 2018-10-18 Seco Tools Ab Compacting device and method for producing a cutting insert green body by compacting a powder
AT522877B1 (en) * 2019-10-04 2021-03-15 Miba Sinter Austria Gmbh Bearing block
AT522877A4 (en) * 2019-10-04 2021-03-15 Miba Sinter Austria Gmbh Bearing block

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EP0682999A3 (en) 1997-05-07
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DE4417663C2 (en) 2003-12-04
DE4417663A1 (en) 1995-11-23
EP0682999B1 (en) 2001-02-07

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